Storage stable detergent composition

ABSTRACT

A CHLORINATED MACHINE DISHWASHING DETERGENT COMPOSITION AND PROCESS OF PREPARING SAME. THE PROCESS INCLUDES SPRAYING A MIXTURE OF A POLY(OXYALKYLENE) GLYCOL DEFOAMER AND A LOW FOAMING ORGANIC, NON-IONIC SURFACTANT ONTO AN AGITATED MASS OF ANHYDROUS DETERGENT SALT. THE MIXTURE IS THEN SPRAYED WITH A SOLUTION OF A WATER-SOLUBLE RESIN. THE REMAINING INGREDIENTS OF THE COMPOSITION TYPICALLY INCLUDING DETERGENT SALTS AND A CHLORINATING AGENT ARE THEN BLENDED WITH THE ENCAPSULATED COMBINATION TO COMPRISE A STORAGE STABLE DETERGENT COMPOSITION WHICH RETAINS BOTH AVAILABLE CHLORINE AND A LOW FOAMING CHARACTERISTICS.

United States Patent 3,703,470 STORAGE STABLE DETERGENT COMPOSITIONWilliam R. Brennan, Cincinnati, Ohio, assignor to Chemed Corporation,Cincinnati, Ohio No Drawing. Filed Oct. 6, 1970, Ser. No. 78,626

Int. Cl. Clld 7/56 US. Cl. 252-99 2 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to a detergent composition including thecombination of a poly(oxylalkylene) glycol defoamer and a low foamingorganic, non-ionic surfactant absorbed onto a detergent salt carrier andencapsulated with a water soluble resin; and to a method for preparingthe said composition. The present composition and method provideimproved storage stability with respect to available chlorine and lowfoaming properties. The composition is particularly suited for machinedishwashing in the presence of proteinaceous matter.

In the past, when both chlorinating agents and low foaming surfactantswere incorporated into a dishwashing detergent composition, considerabledifficulties resulted. The surfactants used in these detergentformulations are readily susceptible to attack by chlorine andparticularly the hypochlorite ion. As a consequence of such reactions,the surfactants break down and in a relatively short period losedesirable detergency properties including the ability to suppress thefoam of proteinaceous soil. The chloride is also dissipated as a resultof the reaction and the overall effectiveness of the dishwashingcomposition is greatly reduced.

The desirability of a non-deteriorating detergent composition includingan organic chlorinating agent and a lower foaming surfactant has beenlong felt in the art.

US. Pat. 3,306,858 to Oberle describes one method of providing storagestability of desired defoaming characteristics. However, thecompositions and method of Oberle fail to provide substantial protectionof the chlorinating agent. During extended storage, compositionsprepared by the Oberle process are subject to a loss of chlorinatingpower.

The present invention provides a means for preparing a highly elfective,storage stable, machine dishwashing detergent composition containingboth a surface active agent and a chlorine releasing agent.

This composition effectively removes food soils from glassware, dishes,eating utensils and the like while providing great storage stability forthe chlorine releasing agent and also retaining desired low foamingcharacteristics during use.

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The chlorine releasing agents are added last after the defoamer andnon-ionic surfactant have been protected by encapsulation. Generallyspeaking, the machine dishwashing composition of this invention isprepared by encapsulating a poly(oxyalkylene) glycol defoamer and a lowfoaming organic, non-ionic surfactant by spraying a mixture of the twoonto an agitated body or mass of an anhydrous alkali metal detergentsalt such as anhydrous sodium carbonate, then coating the mixture byspraying it with a water soluble resin. The resin encapsulating coatingmay be a solution of a resin dissolved in an organic solvent, an aqeuoussolution of an alkali metal salt of a resin containing an acid group, oran emulsion of a resin. The encapsulated defoamer and surfactantcombination is then blended with a chlorine releasing agent and otherdetergent salts normally used in formulating dishwashing typedetergents. I

These dishwashing compositions generally include various detergent saltsincluding alkali salts, condensed alkali metal phosphate salts (alsoknown as alkali metal polyphosphate") and a chlorine releasing agent.Examples of alkalis include sodium and/or potassium hydroxide, mono-,diand tri-sodium or potassium orthophosphates, sodium or potassiumbicarbonate, and sodium or potassium carbonates; or (mixtures of anytwo) or mixtures of any two or more of the foregoing. Useful alkalimetal polyphosphates are tetrasodium pyrophosphate, tetrapotassiumpyrophosphate, sodium tripolyphosphate, potassium pyrophosphate,potassium tripolyphosphate and the like; and mixtures thereof.

Suitable chlorine releasing agents include chlorinated trisodiumphosphate; trichloromelamine; sodium, calcium and lithium hypochlorites;dichloroisocyanuric acid and its water soluble salts such as potassiumdichloroisocyanurate and the like.

The surface active agents useful in the process of this invention arelow foaming organic non'ionic surfactants obtained by condensingalkylene oxide with water insoluble organic compounds, that is alcohols,phenols, thiols, primary and secondary amines, carboxylic and sulfonicacids and their amides. Surfactants of this type are well known in theart. For example, US. Pat. 3,308,067 to Diehl et al. describes a groupof non-ionic surfactants formed by condensing ethylene oxide with alkylphenols, aliphatic alcohols, the reaction product of propylene oxide andethylenediamine, and various other water insoluble organic compounds.

The preferred organic, low foaming non-ionic surfactant for the purposeof this invention is a linear alcohol alkoxylate, such as OlinsPoly-Tergent S 305-LF, a liquid polyalkoxylated aliphatic baseddetergent, 97-100%, non-ionic and non-foaming.

The defoaming agents used in the practice of the invention aremonobutoxy ethers of random oxyethylene-oxypropylene glycols known aspoly(oxyalkylene) glycols. Innumerable examples of suitable glycols aredisclosed in Lissant et al. US. Pat. 3,382,178 issued May 7, 1968,especially column 4, line 55 through column 11, line 3. The entiredisclosure of the said Lissant U.S. Pat. 3,382,178 is herebyincorporated herein by reference thereto.

A preferred poly(oxyalkylene) glycol has a molecular weight of about4000 and is prepared by polymerizing ethylene oxide and 5 0% propyleneoxide.

The anhydrous salts useful as carriers in the process of this inventioninclude anhydrous sodium carbonate, trisodium phosphate, sodiumtripolyphosphate, tetra sodium pyrophosphate, sodium bicarbonate, sodiumsesquicarbonate, sodium borate, and possibly sodium metasilicate andsodium orthosilicate.

The general types of water soluble synthetic resins which are useful inthe process of this invention are:

(1) Cellulose derivatives such as carboxymethylcellulose,carboxyethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose and water soluble salts of such polymers;

(2) Water soluble vinyl polymers such as poly(vinyl alcohol), poly(vinylacetate) partially hydrolyzed poly (vinyl acetate), poly(vinyl methylether), polyvinyl pyrrolidone, and copolymers thereof.

(3) Acrylic polymers such as poly(acrylic acid), poly (methacrylicacid), acrylic acid-methacrylic acid copolymers, copolymers of acrylicacid with other monomers, polyacrylamide, hydrolyzed polyacrylamide,polymethacrylamide, hydrolyzed polymethacrylamide,acrylamidemethacrylamide copolymers, copolymers of acrylamide with othervinyl monomers, polyacrylonitrile, hydrolyzed polyacrylonitn'le,polymethacrylonitrile, hydrolyzed polymeth'acrylonitrile,acrylonitrile-methacrylonitri1e copolymers, and hydrolyzedacrylonitrile-methacrylonitrile copolymers, or the water soluble, (e.-g.the alkali metal, ammonium or amine) salts of such polymers, or mixturesof any two or more of said polymers and/ or water soluble salts.

(4) Maleic copolymers prepared by the copolymerization of maleic acid ormaleic anhydride with a second monomer, such as styrene-maleic anhydridecopolymers.

(5) Other operable synthetic resins are polyethylene, polyethyleneoxide, polypropylene, polypropylene oxide, polythyleneimine and thelike.

The preferred synthetic resins for the purpose of this invention includemethyl cellulose, ethyl cellulose, ethyl hydroxyethylcellulose,styrene-maleic anhydride copolymers, poly(acrylic 'acid) polymers,polyethylene and polypropylene.

The preferred styrene-maleic anhydride copolymer useful in the practiceof this invention is one commercially available from Monsanto Companyunder the name Lytron. This copolymer has an equivalent weight of 295and an acid number of about 190. The copolymer has an average molecularweight within the range of from about 1,500 to 50,000 and preferablyfrom about 5,000 to about 15,000; e.g. 10,000 (Lytron 822").

The polyethylene resin useful in the practice of this invention has amolecular weight within the range of from about 10,000 to about 32,000and preferably from about 16,000 to 28,000. One exemplary suitableproduct is a 55% solids polyethylene emulsion, 16,000 average molecularweight, sold by Gulf Oil Company, US. Chemicals Department, under thetrade name Poly-Em 12.

Suitable acrylic polymers are commercially available from -Rohm & HaasCompany under the trade name Acry- Approximate parts by weightComponents Operable Preierred Coating: Synthetic resin 0.2 to 10.-. 0.5to 5. Encapsulated components:

Deioamlng agent 0.1 to 5...- 0.1 to 3. Non-ionic surfactant 0.1 to 5-..-0.1 to 3.

Anhydrous detergent salt 1 to 60.... 20 to 50.

In the preferred compositions of the present invention the followingcomponents in the amounts indicated are admixed with the encapsulatedparticles.

Approximate parts by weight Components Operable Preferred Sodiumtripolyphosphate 5 to 60. 15 to 45. Tetrasodium pyrophosphate... to20..." 5 to 16. Sodium hydroxide 5 to 30 5 to 20. Sodiumdichloroisoeyanurate 0.5 to 8.... 1 to 5.

The invention is further illustrated by the following non-limitingexamples.

EXAMPLE 1 A detergent composition was prepared from the followingingredients in the amounts indicated:

Components: Parts by wt. Sodium carbonate, anhydrous 45.0Poly(oxyalkylene) glycol defoamer 1.6

Linear alcohol alkoxylate (Olins Poly-Tergent S-305-LF) 0.4

Solution of ethyl cellulose dissolved in ethyl alcohol I 3.0 Sodiumtripolyphosphate 15.0 Tetrasodium pyrophosphate 15.0 Sodium hydroxide16.5 Sodium dichloroisocyanurate 3.5

The poly(oxyalkylene) glycol, and linear alcohol alkoxylate are mixedtogether and sprayed onto the sodium carbonate while being agitated in asuitable mixer. The solution of ethyl cellulose dissolved in ethylalcohol is sprayed onto the above mixture thus forming a capsule. Theother ingredients are sequentially added to the mixer in the tabulatedorder.

A sample of the above composition was tested according to the usualprocedures and was found to be an efl'ective machine dishwashingdetergent.

EXAMPLE 2 In this example, the encapsulating coating is made of anaqueous sodium salt solution of a styrene-maleic anhydride copolymer.

A detergent composition was prepared from the fol- The polyoxyal'kyleneglycol and linear alcohol alkoxylate are mixed together and sprayed ontothe anhydrous sodium carbonate while being agitated in a suitable mixer.The aqueous solution of styrene maleic anhydride resin is sprayed ontothe above mixture thus forming a capsule. The other ingredients aresequentially added to the mixer in the tabulated order.

A sample of the above composition was tested according to the usualprocedures and was found to be an effective machine dishwashingdetergent.

EXAMPLE 3 In this example, the encapsulating coating is made of anemulsion of a low molecular weight polyethylene.

A detergent composition was prepared from the following ingredients inamounts indicated:

Components: Parts by wt. Sodium carbonate, anhydrous 45.5Poly(oxyal'kylene) glycol 1.0

Linear alcohol alkoxylate (as in Example 1) 1.0 Aqueous 55 percentemulsion of low molecular weight (16,000) polyethylene (Poly- Em 12) 2.5Sodium tripolyphosphate 15.0 Tetrasodium pyrop hosphate 15.0 Sodiumhydroxide 16.5 Sodium dichloroisocyanurate 3.5

The polyoxyal kylene glycol and linear alcohol alkoxylate are mixedtogether and sprayed onto the anhydrous sodium carbonate while beingagitated in a suitable mixer. The aqueous polyethylene emulsion issprayed onto the above mixture thus forming a capsule. The otheringredients are sequentially added to the mixer in the tabulated order.

A sample of the above composition was tested according to the usualprocedures and was found to be an effective machine dishwashingdetergent.

EXAMPLE 4 In this example, the encapsulating coating is made of anemulsion of an acrylic resin.

A detergent composition was prepared from the following ingredients inamounts indicated:

Components: Parts by wt. Sodium carbonate, anhydrous 45.5 Poly(oxyalkylene) glycol 1.0 Linear alcohol alkoxylate 1.0

Aqueous emulsion of a high molecular weight acrylic acid copolymer resin(Acrysol ASE The polyoxyalkylene glycol and linear alcohol alkoxylateare mixed together and sprayed onto the anhydrous sodium carbonate whilebeing agitated in a suitable mixer. The aqueous emulsion of acrylic acidcopolymer resin is sprayed onto the above mixture thus forming acapsule. The other ingredients are sequentially added to the mixer inthe tabulated order.

A sample of the above composition was tested according to the usualprocedure and was found to be an effective machine dishwashingdetergent.

The following test was employed to evaluate the defoaming stability ofdetergents prepared in accordance with the process of this invention.

Sample solutions for foam height measurements are prepared by dissolving1.5 grams of the compositions of Examples 1, 2, 3 and 4 in 500milliliters of water, heating to 70 centigrade and immediately addingthe heated solution to a Waring Blendor which contains 1.0 gram ofnon-fat dried milk. The components are mixed for about 30 seconds in theblender, and the foam is measured at the moment that a definite line ofdemarcation is observed in the aqueous mixture.

Results are given for the compositions of Examples .1, 2, 3, and 4.

Foam heightin inches Storage time, Initial Stored 1 months Examples:

% 6 l6 6 M 1 4 l6 4 1 At 70-80 Fahrenheit.

Available chlorine retention tests were also performed. The availablechlorine is determined by a conventional iodometric titration procedureknown in the art. Results are given in Table II for the compositions ofExamples 1, 2, 3 and 4.

1 At 70-80 Fahrenheit.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit or scope of this invention.

What is claimed is:

1. A machine dishwashing composition which consists essentially of:

(I) on encapsulated component consisting of: approximate 0.1 to 5 partsby weight of defoaming agent, approximate 0.1 to 5 parts by weight of alow foaming non-ionic surfactant, approximate 1 to 60 parts by weight ofan anhydrous detergent salt, said defoaming agent and said surfactantbeing absorbed into the anhydrous detergent salt, and approximate 0.2 toabout 10 parts by weight of a synthetic resin coating disposed about thesaid salt with absorbed ingredients; said defoaming agent beingpoly(oxyalkylene) glycol having a molecular weight of about 4,000 andhaving 50% ethylene oxide polymerized with 50% propylene oxide; said lowfoaming nonionic surfactant being linear alcohol alkoxylate; saidanhydrous detergent salt being selected from the group consisting of theanhydrous salts of sodium carbonate, tri-sodium phosphate, sodiumtripolyphosphate, tetrasodium pyrophosphate, sodium bicarbonate, sodiumsesquicarbonate and sodium borate; said resin selected from the groupconsisting of ethyl cellulose, methyl cellulose, ethylhydroxyethylcellulose, styrene-maleic acid copolymers, acrylic acidcopolymers, and low molecular weight polyethylene; and blended with (I);

(II) approximate 0.5 to 8 parts by weight of a chlorine release agentselected from the group consisting of chlorinated trisodium phosphate,trichloromelamine, sodium hypochlorite, calcium hypochlorite, lithiumhypochlorite, sodium dichloroisocyanurate and potassiumdichloroisocyanurate;

(III) approximate 5 to 30 parts by weight of an alkali componentselected from the group consisting of sodium hydroxide, potassiumhydroxide, mono-, di-, and tri-sodium or potassium orthophosphate,sodium or potassium bicarbonate, and sodium or potassium carbonate;

(IV) approximate 1 to 20 parts by weight of alkali metal polyphosphateselected from the group consisting of tetrasodium pyrophosphate andtetrapotassium pyrophosphate; and

(V) approximate 5 to 60 parts by weight of alkali tripolyphosphateselected from the group consisting of sodium tripolyphosphate andpotassium tripolyphosphate'.

2. The composition of claim 1 wherein:

(I) said defoaming agent is present in approximate 0.1 to 3 parts byweight, said surfactant is present in approximate 0.1 to 3 parts byweight, said detergent salt is present in approximate 20 to 50 parts byweight, and said resin is present in approximate 0.5 to 5 parts byweight;

'(II) said chlorine release agent is present in approximate 1 to 5 partsby weight;

(III) said alkali component is present in approximate 5 to 20 parts byweight;

(IV) said alkali metal polyphosphate is present in approximate 5 to 15parts by weight; and

(V) said alkali tripolyphosphate is present in approximate 15 to 45parts by weight.

References Cited UNITED STATES PATENTS RICHARD D. LOVERING, PrimaryExaminer U.S. Cl. XJR.

l17-l00 A, 100 B, 100 S; 252-3l6, DIG. 1, DIG. 2, DIG. 3, DIG. 1O

